What does Hebrews 6:20 mean?

The previous verses blended three distinct images into a single, powerful, encouraging point. Christ's work on our behalf combines the principles of a refuge, an anchor, and the Holiest of Holies of the Old Testament temple. Mixed together, the message is that Christ has gone ahead of us, as our example and our High Priest, and anchored our hope. That anchor is not affixed here, in our present circumstances, but in the ultimate source of truth and holiness. For this reason, we can be confident in the promises of God (Hebrews 6:18), and hold fast (Hebrews 3:6; 4:14), to a confident and growing spiritual maturity, in both truth and love.

This verse uses the Greek term prodromos, translated into English as "forerunner." This is similar to the reference in Hebrews 2:10, which used the word archēgon to call Jesus the "captain," or "author" or "founder," of our salvation. This helps to blend the reference to an anchor with Christ's entry into the inner sanctuary; sailors would often carry a ship's anchor to a more secure point in order to attach the anchor as solidly as possible.

The final statement of this verse ties together this gradual flow from warning (Hebrews 5:11—6:8), to praise (Hebrews 6:9–12), to encouragement (Hebrews 6:13–19), and finally back to the original topic: the priesthood of Melchizedek. Masterfully, the writer does this by referring to yet another promise of God, and one already used in this book: that of Psalm 110:4. This same promise was previously applied to the priesthood of Christ (Hebrews 5:6), just prior to the warnings of chapter 6, bringing the discussion full-circle.